Unit 6- Topic 5 Flashcards
Operons
A group of genes that can be turned on or off
Promoter
Where RNA Polymerase can attach
Operator
The on/off switch
Genes
Code for related enzymes in pathway
Apoptosis
Programmed cell death
Operons can be either
repressible or inducible
Repressible
transcription on to off
Inducible
transcription off to on
Allosteric Activator
substrate binds to allosteric site and stabilizes the shape of the enzyme so that the active sites remain open (active form).
Allosteric Inhibitor
substrate binds to allosteric site & stabilizes the enzyme shape so that the active sites are closed (inactive form).
Histone acetylation
adds acetyl groups to histones, which loosens the dna
dna methylation
adds methyl groups to DNA, which causes the chromatin to condense
Differentiation
cells become specialized in their structure and function
Morphogenesis
the physical process that gives an organism its shape
Cytoplasmic determinant
substances in the maternal egg that influence cells
Induction
cell to cell signals that can cause a change in gene expression
Pattern formation
a “body plan” for the organism
Homeotic genes
map out the body structures
Epigenetic inheitance
chromatin modifications do not alter the nucleotide sequence of the DNA, but they can be heritable to future generations.
modifications can be reversed, unlike mutations.
why 1 twin can inherit a disease and the other does not.
Regulatory gene
produces a repressor protein that binds to the operator to block RNA polymerase from transcribing the gene.
expressed low levels
binding of a repressor to an operator is reversible
